A peristaltic pump is a pump in which fluid is forced along by cycles of contraction produced mechanically on flexible tubing. One advantage of peristaltic pumps is that the pump mechanism is separated from the fluid being pumped within the flexible tubing, which can help reduce contamination of the fluid by the pump and can help reduce clogging or fouling issues. Various configurations of peristaltic pumps have been developed to date.
In one approach, e.g., as considered in U.S. Pat. No. 6,942,473, members mechanically engage with the tube to provide input valve action, output valve action, and pumping. In another approach, e.g., as considered in U.S. Pat. No. 6,743,204, a roller assembly in contact with the flexible tube creates a compression of the flexible tube that is moved along the tube to provide pumping action. In U.S. Pat. No. 6,024,545, a similar approach is considered, where a ring-shaped pressure member creates a moving compression point in the flexible tube to provide pumping action.
However, these conventional approaches can have some significant disadvantages. Approaches that rely on separate members for input valve action, output valve action, and pumping may require more complex mechanical designs to provide the appropriate operation sequence. For example, multiple actuators may be necessary. Approaches that rely on moving a point of compression along the flexible tube (e.g., rotary peristaltic pumps) can suffer from reduced mechanical efficiency and can lead more quickly to unwanted permanent deformation of the tubing.
Accordingly, it would be an advance in the art to provide improved pumping performance with pumps having a simpler mechanical configuration than conventional approaches, and to provide such pumps capable of being driven with a single actuator.